This invention relates to the use of 1,1,1,4,4,4-hexafluorobutane (R 356) as an insulating gas and blowing agent for the production of foam plastics, especially isocyanate-based foams and preferably polyurethane foams.
It is known that foams are produced using blowing agents. In closed-cell foams, the blowing agents also act as a o heat-insulating cell gas. The fluorocarbons trichlorofluoromethane (R 11), dichlorodifluoromethane (R 12), trichlorofluoroethane (R 113), and the like, are among the most widely used insulating and blowing gases for foams of polyurethane, polystyrene, polyvinylchloride, phenol-formaldehyde, and others. However, a disadvantage of these halogenated products is their ability, due in part to their high stability, to enter the stratosphere where they are said, because of their chlorine content, to contribute to the degradation of ozone in the stratosphere. For this reason, the world production of chlorofluorocarbons is now limited.
The object of the present invention is to provide insulating gases and blowing agents for the production of foam plastics which cannot damage the ozone layer. This object is achieved by using as the insulating and blowing gas according to the invention, 1,1,1,4,4,4-hexafluorobutane.